As in English, there are quite a
few different ways to say hello and goodbye and there are many more regional differences than shown here (for
a more complete list, click here), but
these examples are probably the most common and most important ones. You should
get familiar with them, they are all used very frequently. (Hallo and Tschüss being the most universal ones).

Are you alone?
Are you alone at home?
Are you {polite} alone at home?
Are you coming to Jannik’s?
Are coming alone?
Are you {polite} coming to Mr Schmidt’s?
Are you [polite] coming alone?
Are you going to Anne’s?
Are you going to Ms. Stern?